According to the teachings of the Buddhist and Hindu religions, attaining nirvana is to enter a state of supreme liberation, leaving behind the
desires that perpetuate the cycle of death and rebirth.
(A) attaining nirvana is to enter
(B) to attain nirvana is entering
(C) to attain nirvana is
(D) to attain nirvana is to enter
(E) attaining nirvana is to be entering
OA: D
Can the instructor please explain, why B is incorrect. Since entering is parallel to leaving.
source Kaplan GMAT